Contactless proximity sensor with multilevel response
US4424458A · kind A · utility
14Cited by
4References
5Claims
0Family size
Inventors
Key dates
| Filing date | Oct 7, 1981 |
| Grant date | Jan 3, 1984 |
| Priority date | — |
| Expiry date | Oct 7, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B23/00
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A signal detector of a contactless proximity sensor feeds three voltage comparators with reference inputs connected to points of different threshold potentials. When the incoming signal exceeds only the lowest threshold, a light-emitting diode is flashed at a low frequency; when the intermediate threshold is surpassed, the diode flashes at a higher frequency, whereas its light emission is continuous in the presence of a signal level above the highest threshold. Only in the last two instances will a load-control circuit be switched.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.